Annular saws that rotate and which are driven by the friction of a roller acting on a saw blade are well known. For example, the Santilli U.S. Pat. No. Re 27,716 discloses an annular saw with a circular safety guard. As disclosed therein conical rollers rotate an annular saw blade about an axis. This saw blade includes a plurality of cutting teeth about the periphery of the blade. A portion of the saw blade is protected by a casing. As disclosed, in the patent, the saw blade is provided with a circular guard which conceals nearly the entire saw blade's tooth periphery and gradually exposes it only when the workpiece is fed to the saw.
Apparatus for damping vibrations of rotary cutting blades are also known. For example, the U.S. Patent of Allison, U.S. Pat. No. 3,797,354 discloses such apparatus. As disclosed therein, the planar surface of a rotary cutting blade is frictionally contacted by a damping means comprising a plurality of coaxial independent rotatable discs each presenting a relatively narrow peripheral surface in contact with the planar surface and intersecting the axis of rotation of the cutting blade. The apparatus includes a frusto-conical surface or a plurality of spaced coaxially frusto-conical roller segments. Means are provided for adjusting the frictional contact between the damping means and the planar surface.
My copending application entitled Electric Powered Rotary Hacksaw, Ser. No. 10/314,979 which was filed on Dec. 10, 2002 discloses an electric powered rotary hacksaw which includes a cylindrical housing, an integral longitudinally extending mounting member and a rotary circular hacksaw blade disposed on one end of the mounting member. The hacksaw blade is fixed to a shaft for rotation about an axis which is generally perpendicular to the longitudinal axis of a mounting member. A variable speed electric motor is disposed in the housing and includes a shaft, one end of which extends outwardly out of the housing in a direction which is generally parallel with a longitudinal member. A frusto-conical driver made of an elastomeric material is fixed to the end of the shaft and engages the circular blade to displace a portion of the blade out of the normal plane of rotation by an angle of about 5° and for rotating the circular blade.
Notwithstanding the above, it is presently believed that there may be a commercial demand for an improved electric powered rotary saw in accordance with the present invention. It is believed that there may be a demand for an improved electric powered rotary saw for cutting medical casts and for other applications. It is also believed that there may even be a greater commercial demand for an adapter in accordance with the present invention which enables an individual to convert a conventional electric powered rotary saw to an electric powered rotary saw in accordance with the present invention.
Further, the improved electric powered electric saw and adapter in accordance with the present invention are relatively light in weight, free from unnecessary vibration, durable, can be manufactured and sold at competitive prices and adaptable to various applications.